Gillham code: Difference between revisions

Revision as of 05:03, 14 August 2022

Revision as of 07:31, 14 August 2022

Line 270:

== Decoding ==

{{Disputed section|date=August 2022|The "Altitude Encoder" and "Decoding the Gillham Code" sections}}

Bits D2 (msbit) through B4 (lsbit) encode the pressure altitude in 500&nbsp;ft increments (above a base altitude of −1000±250&nbsp;ft) in a standard 8-bit [[reflected binary code]] (Gray code).<ref name="Phillips_1998_ASCII"/><ref name="Stewart_2010"/><ref name="Gray_1947"/><ref name="Steinbuch_1962"/><ref name="Steinbuch-Weber_1974"/> The specification stops at code 1000000 (126500±250&nbsp;ft), above which D1 would be needed as a most significant bit.